According to AddThis data, adoption of Yosemite hit 2% on the first day. That compares to 1.2% adoption of Mac OS X 10.9 Mavericks when it was released in October 2013.

The faster clip is not entirely surprising. Yosemite was considered by many to be a more significant upgrade than Mavericks. And it offered a number of new features that allowed for tighter integration with iPhones or iPads that run iOS 8.

AddThis, which provides a social sharing and bookmarking tool, is used on 13 million websites, and says it collected its data via those integrations.